Apparatus and method for molding conduits and the like



Dec, 30, 1924.

T. E. MURRAY APPARATUS AND METHOD FOR MOLDING GONDUITS AND THE LIKEFiled Feb. 4, 1924 3 Sheets-Sheet l Dec. 30, 1924.

T. E. MURRAY APPARATUS AND METHOD FOR MOLDING CONDUITS AND THE LIKE lINVENTOR. I .jf/frag ,wf/y

ATTORNEY miin .l I. l a

3 Sheets-Sheet 2 Filed Feb. 4, 1924 Dec, 30, 1924.

T.E. MURRAY APPARATUS AND METHOD FOR MOLDING CONDUITS AND THE LIKE 5Sheets-Sheet 5 Filed Feb. 4, 1924 TTOR N5 Y l Patented De.3o,1`924.

UNITED STATES PATENT OFFICE.

THOMAS E. MURRAY, OF BROOKLYN. NEW YORK, I

APPARATUS AND METHOD FoR'ivroLDING coNDUI'rs AND THE LIKE.

f Application mea February 4, 1924. serial No. 690,412.

To all whom t may concern.

Beit known that I, THOMAS E. MURRAY,

a citizen of the United States, and a resident of the borough ofBrooklyn, county of Kings, and State of New York, have invented certainnew and useful Improvements in Apparatus and Methods for Moldin Conduitsand the like, of which the follow ing'is a specification. i

The. invention is particularly applicable to the laying of concretestructures carrying a number of ducts generally of a few inches indiameter for electric cables. It is applicable also to other. plasticmaterials than concrete and to the forming of structures with openingsof various sizes and shapes and for various uses. It is particularlyuseful in the laying of such conduits underground, though applicablealso to structures built above 2o ground. The accompanying drawingsillustrate embodiments of the invention.

Fig. 1 Iis a perspective view, with an end in vertical section, showingone stage in the forming of conduits underground;

Figs. 2, 3 and 4 are vertical sectionsf illustrating successive stagesin the operation;

Figs. 5, `6, 7 and 8 are perspective views illustrating modified formsof the apparatus:

Figs. 9 and 10 are perspective views of still other forms.

Referring to the embodiments of the invention illustrated. a conduit, inwhich term I include the entire concrete structure, is shown at 1,Fight, with a number of longitudinally extending ducts 2 formed therein.The ducts illustrated are circular but. they may be of other shapes incross-section. The conduit 1 of Fig. 4 has six pairs of parallel ductsin vertical arrangement. Fig. 1 illustrates the building of a pair ofsuch ducts at opposite sides of an excavation. ,Generally these will beconnected at the bottom byga. third conduit (1, Fig. 4) extendinghorizontally 'and which may be formed vby the same method.

The necessary excavation being made in ,s the earth 3, mold boards 4 areset up with 'braces 5 between them engaging stieners 6', .leaving spacesbetween the mold boards and the sides of the excavation for the concretewhich is cast or poured in from the top.

' The ducts areformed by casting the concrete around cores 1.7. Theseare preferably rubber cores which after the concrete has sufficientlyhardened are removed by pull-- ing them out endwise as described incertain 'previous applications for patent which I have tiled(particularly Nos. 670,423 and 679,521). Various other styles of coremay be used, however, and they may be removable or may be permanent,serving as linings for the ducts. The present invention is' directedparticularly to the,4 holding of such cores properly spaced during thecasting of the concrete.

A post '8, preferably circular to facilitate the ,turning of it in thewet concrete, is suspended from an overhead cross-beam 9 resting on theedges of the mold boards; each post being provided at the top with anangle i or ange 10` which is fastened by means of a removable pin 11 toan upright flange of the cross-beamv 9; The post lhas holes extendinghorizontally through it at .properly spaced intervals, and through theseholes are passed pins 12. ',lhe pins have eyes at one end and arearranged in alternate positions with the eyes at -opposite sides. Rods13 pass down through the eyes of the pins 12 at the opposite sides,being loose in the eyes so that they may be easily inserted and4withdrawn. The cores 7 are carried in the venclosures formed by thestructure thus assembled. The posts 8 serve as llateral spacers for thecores. The pins 12 support the weight of the cores and also support themagainst upward movement under pressure from the wet concrete; thesupporting structures described being arranged along vthe length of thecoresat sufficient intervals to prevent the sagging thereof to anobjectionable extent. The concrete being poured to the desired level,Athe supporting structurel described may be removed as statedhereinafter, wliile the concrete is suiiciently plastic to fill thevoids caused by such removal;

or additional grout being poured in the voids thus left. Where the coresare to be withdrawn it is necessary to withdraw the entire.

iare the usual permanentlim'ngs of non-conlos ducting fibre or the likethe supporting the rods 13 are pulled out.

structure may be left in the concrete or may be partly withdrawn. Forexample, the rods 13 may be withdrawn to save them for furinchesdiameter and the pins 12 and rods 13 of stiff' wire three-eighths 'of aninch in diameter. A handle may be, fastened to the top of the post forturning and lifting it, or the cross-beam 9 may be used for thispurpose. u l

' The ositionmg means for the cores may be modified asm Fig. forexample. Here the central post is a flat bar 14 with a handle J15 fixedo'n its upper end and with a wire 16 l weldedto its edges as intervalswith horizontal portions serving to hold the cores 7 'against upward andldownward pressures and with eyes formed ofloops 17 at the outer endsofv the horizontal portions receiving and holding the vertical rods 13which hold the cores in position against outward lateral movement. Inthis figure I have shown also a substitute for the rods 13 in the formof a fiexible wire or cable 18 which may be passed back and forththrough the bends of the wire 16 and broughtup at the other endto pullit taut; and which, after the concrete is poured, can be withdrawn bypulling up the looped end 19.

According to Fig.,y 6 a round post 20 is' -used with horizontal loops ofwire 21 passing through it and at their outer ends serving to engage therod 13 or thefiexible wire or cable 18. yIn Fig. 7 a flat bar 14,similar to that of Fig. 5, is shown with separate single cross wires 22welded to one face of the post and having eyes at their opposite endsto'receive the rods 13 or the like. l y

The method of withdrawal of the parts shown in Figs. 5, 6 and 7 is thesame as for bers.

Fig. 1. The central post-in these figures, however, is pointed at theend and is intended to be thrust into the ground to the desired depth,instead yof being supported from overhead; being rovided with a hanlidle15 at the upper en` ,for pullin it out. -I have designed ltheseparticularly or smaller;

eliminate the separate side rods 13. It shows also the use of additionalspacing means between the cores. A central post 14 similar to that ofFig.\5 is u-sed. It carries, welded or otherwise fastened to it,horizontal wires 23 the out-er ends 24 ofwhich are curved alternately upand down so as to embrace the cores 7 and prevent their displacementlaterally outward as well as up and down. The width of the central post14 is less than the desired spacing between the ducts. Immediatelybeyond the side edges of the post 14 the wires 23 are bent to form loops25 which serve as guides to hold spacing rods 26 which pass down throughthem and which bear against the cores 7 to hold the latter out to thedesired spacing.

The apparatus of Fig., 9 is illustrated in connection with a conduithaving three ducts in each horizontal course. The cores 27 are assumedto be permanent linings -of paper or similar material but removablecores can be equally wellused. A hollow central spacing post 28 is usedbeing supported near its upper end by means of a clamp 29 fastened byafnut 30. A number of Such clamps are arranged on a bar 31 which restson jacks 32 or other convenient parts of the structure. Each post4carries cross rods or pins 12 with eyes through which pass theretaining rods 13.' The point of support of the central post 28 being atits upper end there is a chance of its swaying while the concrete isbeing cast. To prevent this a pointed rod 33 is I passed down throughthe hollow post and into Jthe ground below. The pins 12 passtransversely through the hollow post also. But they and the stay-rod 33are so small that both can be easily accommodated within l the post. v,

The arrangement described takes care of two ducts in a course. Toprovide for three there are similar structures arranged alternately on.opposite sides of the overhead bar 31. For example, the first post 28is indicated at the ri ht ofthe bar. The next one 28a is mounted on theleft. It will carry pins 12, retaining rods 13 and a stay-rod 33 downthrough its center; 'these-parts being' omitted from the figure for thesake ofY clearnes's. Thus the central core 27 will be supported at twiceas many points as `the two outsidecores.

The strains tending to throw the cores and the supporting structuretherefor laterally out of llne are kgreatest at the bottom.Y rlhe splkeor stay-rod 33 stays the parts at the stiff overhead structure shownserves to maintain an accurate location of the central spacing posts andconnecting parts.

Where the conduit branches oli' into a smaller trench without false-workor other supporting structure therein the scheme of Fig. 10 may be used.Angle irons 34 are laid across the trench at intervals with sufiicientbearing at the sides to carry the weight. The vertical flange hasopenings for receiving a looped clamping rod the ends of which arethreaded and provided with fastening nuts 36. The central post 28carrying the cross wires 12 is fastened firmly to the supporting bars 34withits lower end near the bottom of the trench and is then stayed bypassing the long spike or stayrod 33 through it and into the ground.

This scheme is particularly useful, even though it may be ,on largetrenches supplied with other supporting material, where theo conduit isto go around a curve. The bars 34 are freely adjustable to the curvatureof the trench. And after a spacing post 28 has been clamped to a bar 34the .latter may be moved in any horizontal direction to get exactly theright osition. This may be done after the cores 2 are embraced in theframe work of rods 12 and 13. or before.

Though I have described with great particularity of detail certainembodiments of my invention, yet it is not to be understood therefromthat the invention is restricted to the particular embodimentsdisclosed. Va-

riousmodifications thereof in detail and in the arrangement ofthe partsand in the order of the steps of the process may be made by thoseskilled in the art without departing from the invention as defined inthe followmg claims.

What I claim is 1. The method of forming a structure of plastic materialwith an opening therein which consists in holding a core in place byremovable positioning means outside of the core, casting the plasticmaterial about said core and positioning means and withdrawing thelatter.

2. The method of forming a struct-ure of plastic material with anopening therein which consists in holding a core in place by removablepositioning means, casting lthe plastic material about said core andpositioning means, withdrawing the latter while the material is stillplastic and withdrawing the core when the plastic material has hardened.

3. The method of forming a structure of plastic material with ductstherein at different levels which consists in holding cores for saidducts at their respective levels by removable positioning means, castingthe plastic material about the cores and positioning means andwithdrawing the latter.

4. The. method of forming a structure of plastic mate-rial with ductstherein at different levels which consists in holding cores forsaidducts at their respective levels by removable positioning means, castingthe plastic material about the cores and positioning means, withdrawingthe latter whilethe material is still plastic and withdrawing the coreswhen the material has hardened.

5. The method of forming a struct-ure of plastic material with anopening therein which consists in holding a core in place by removablepositioning means extending horizontally, casting the plastic materialabout the core and saidpositioning means and moving the latter throughthe plastic material horizontally out of line with the core andvertically out of the material.

6. The method of forming a structure of plasticpmaterial with an openingtherein which consists in holding a core in place by removablepositioning means extending vertically alongside of it, casting 'theplastic material about the core and said positioning means. andwithdrawing the latter in a vertical direction out of the material.

7. An apparatus of the class described including in combination anoverhead structure and a core-positioning means adapted to be suspendedtherefrom to position the core during the casting of the plasticmaterial and adapted to be withdrawn from the plastic material.

8. An` apparatus of the class described including vertical andhorizontal members for through the plastic material to positions out ofline with the cores and the vertical and horizontal members beingmovable in vertical direction through `and out of the plastic material,in combination with secondary vertical members arranged to prevent.lateral displacement of the cores an to be separately withdrawn.

' 10. An apparatus of' he class described including a vertical post,lateral armscarried thereby and a second vertical member engaged by saidarms and thereby held against lateral displacement, said second verticalmember being separately movable from the plastic material and saidvertical post being removable with said lateral arms.

l1. An apparatus of the class descriloely horizontal members befv ovablein` a including in combination horizontally revertical directionthrough-andl out of the movable cores and core-positioning meansplastic'material. 10

comprising vertical and horizontal members, ln Witness whereof, l havehereunto 5 said horizontal members movable laterally sighed my name.

through the plastic material to positions out of line with the cores andthe vertical and THMAS E. MURRAY.'

